SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5ac9eaf54f6ba8626f75e903a0bfaf1dd2c13f225bb8ee81161015ebee55a55d' 
  AND token = 'jRrUbH/k7x/qkjUl118zz3kdg7AY09gm9YbkOAOtkBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}